Year Number of 1990 1730.59 1991 1825.14 1992 1899.5 1993 1978.06 1994 2058.13 1995 2139.7 1996 2226.76 1997 2258.63 1998 2353.92 1999 2430.46 2000 2562.93 2001 2689.8 2002 2788.86 2003 2887.29 2004 3001.18 2005 3115.2 2006 3270.65 2007 3459.14 2008 3653.64 2009 3864.16 2010 4086.74 2011 4225.27 2012 4396.63 2013 4579.32 2014 4725.57 2015 4847.39 2016 5092.55